I found out I was pregnant on April 25. They did an ultrasound that day but saw nothing because I was too early. I went back to the doc yesterday and they're estimating me being 7 1/2 weeks based on the day of my last period. But they saw no heartbeat on the ultrasound and said the baby may have stopped growing and I may end up miscarrying. I am really nervous and scared but I don't see how I can be 7 weeks and they expect a heartbeat when just 3 WEEKS AGO there was nothing. There was an embryo yesterday and I saw it but surely it is the correct size it should be since there was nothing on the ultrasound 3 weeks ago. Any advice would be great...